I think we may be witnessing the breakup of the Republican Party. The Republican coalition (anti-tax wealthy, neo-cons, religious fundamentalists, and Southern racists) is to dogmatic too hold up as a minority party. Each wing bitterly hates the others.
The Base seems to have coalesced around a Southern, openly racist philosophy that is leaning toward regional secessionism. Non-racists Republicans, the RINOs, are being ruthlessly attacked, but they are many of the party's leaders and most of their funding sources. The tea parties now routinely boo Republican politicians. The neo-cons and the movement conservatives are in open warfare now they don't have a real war to forge a common bond over.
When Sarah Palin said she will campaign for non-Republicans it is being interpreted as meaning she will campaign for select conservative Democrats. That is a mistake, what she was saying in a not very subtle way is that she will back the formation of a third party. The Vanity Fair article and her quitting as governor immediately after mark her irreconcilable break with the Republican Party.
If Palin keeps her promise (always problematic) then she may well do to the Republican Party what the Locofocos did to the antebellum Democratic Party. Sister Sarah is truly the gift that keeps on giving.